379 research outputs found

    MTHFR C677T genotype and small vessel disease

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    BACKGROUND AND PURPOSE: Elevated plasma homocysteine levels are associated with stroke. However, this might be a reflection of bias or confounding because trials have failed to demonstrate an effect from homocysteine lowering in stroke patients, although a possible benefit has been suggested in lacunar stroke. Genetic studies could potentially overcome these issues because genetic variants are inherited randomly and are fixed at conception. Therefore, we tested the homocysteine levels-associated genetic variant MTHFR C677T for association with magnetic resonance imaging-confirmed lacunar stroke and compared this with associations with large artery and cardioembolic stroke subtypes. METHODS: We included 1359 magnetic resonance imaging-confirmed lacunar stroke cases, 1824 large artery stroke cases, 1970 cardioembolic stroke cases, and 14 448 controls, all of European ancestry. Furthermore, we studied 3670 ischemic stroke patients in whom white matter hyperintensities volume was measured. We tested MTHFR C677T for association with stroke subtypes and white matter hyperintensities volume. Because of the established association of homocysteine with hypertension, we additionally stratified for hypertension status. RESULTS: MTHFR C677T was associated with lacunar stroke (P=0.0003) and white matter hyperintensity volume (P=0.04), but not with the other stroke subtypes. Stratifying the lacunar stroke cases for hypertension status confirmed this association in hypertensive individuals (P=0.0002), but not in normotensive individuals (P=0.30). CONCLUSIONS: MTHFR C677T was associated with magnetic resonance imaging-confirmed lacunar stroke, but not large artery or cardioembolic stroke. The association may act through increased susceptibility to, or interaction with, high blood pressure. This heterogeneity of association might explain the lack of effect of lowering homocysteine in secondary prevention trials which included all strokes.Collection of the UK Young Lacunar Stroke DNA Study (DNA Lacunar) was primarily supported by the Wellcome Trust (WT072952) with additional support from the Stroke Association (TSA 2010/01). Genotyping of the DNA Lacunar samples, and Dr Traylor, were supported by a Stroke Association Grant (TSA 2013/01). Genotyping of WTCCC2 ischaemic stroke study was funded by the Wellcome Trust. The Oxford Vascular Study has been funded by Wellcome Trust, Wolfson Foundation, UK Stroke Association, British Heart Foundation, Dunhill Medical Trust, National Institute of Health Research (NIHR), Medical Research Council, and the NIHR Oxford Biomedical Research Centre. Funding for the genotyping at Massachusetts General Hospital was provided by the Massachusetts General Hospital-Deane Institute for the Integrative Study of Atrial Fibrillation and Stroke and the National Institute of Neurological Disorders and Stroke (U01 NS069208). Dr Rutten-Jacobs was supported by a Stroke Association / British Heart Foundation programme grant (TSA BHF 2010/01). Dr Adib-Samii was supported by a Medical Research Council (United Kingdom) training fellowship. Dr Markus and Dr Bevan are supported by the National Institute for Health Research Cambridge University Hospitals Comprehensive Biomedical Research Centre. Dr Markus is supported by a National Institute for Health Research Senior Investigator award. Dr Thijs is supported by a Clinical Investigator Grant from the scientific research fund, Fonds Wetenschappelijk Onderzoek Flanders. Dr Levi is supported by a National Health and Medical Research Council (NHMRC Australia) Practitioner Fellowship and the Australian Stroke Genetics Collaboration has received Project Grant support from the NHMRC (App 1010287). Dr Rost was supported by a National Institute of Neurological Disorders and Stroke grant (R01 NS082285-01). Professor Rothwell is in receipt of an NIHR Senior Investigator Award and a Wellcome Trust Senior Investigator Award. We also acknowledge the use of the facilities of the Acute Vascular Imaging Centre, Oxford and the Cardiovascular Clinical Research Facility, Oxford. The sponsors of the study had no role in the study design, data collection, data analysis, interpretation, writing of the manuscript, or the decision to submit the manuscript for publication.This is the final version of the article. It first appeared from the American Heart Association via http://dx.doi.org/10.1161/STROKEAHA.115.01154

    Integrated market selection and production planning: Complexity and solution approaches

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    Emphasis on effective demand management is becoming increasingly recognized as an important factor in operations performance. Operations models that account for supply costs and constraints as well as a supplier's ability to influence demand characteristics can lead to an improved match between supply and demand. This paper presents a class of optimization models that allow a supplier to select, from a set of potential markets, those markets that provide maximum profit when production/procurement economies of scale exist in the supply process. The resulting optimization problem we study possesses an interesting structure and we show that although the general problem is NP -complete, a number of relevant and practical special cases can be solved in polynomial time. We also provide a computationally very efficient and intuitively attractive heuristic solution procedure that performs extremely well on a large number of test instances

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

    Presidential Commission on the Supreme Court of the United States Final Report

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    On April 9, 2021, President Joseph R. Biden, Jr. issued Executive Order 14023 establishing this Commission, to consist of “individuals having experience with and knowledge of the Federal judiciary and the Supreme Court of the United States.” The Order charged the Commission with producing a report for the President that addresses three sets of questions. First, the Report should include “[a]n account of the contemporary commentary and debate about the role and operation of the Supreme Court in our constitutional system and about the functioning of the constitutional process by which the President nominates and, by and with the advice and consent of the Senate, appoints Justices to the Supreme Court.” Second, the Report should consider the “historical background of other periods in the Nation’s history when the Supreme Court’s role and the nominations and advice-and-consent process were subject to critical assessment and prompted proposals for reform.” Third, the Report should provide an analysis of the principal arguments for and against particular proposals to reform the Supreme Court, “including an appraisal of [their] merits and legality,” and should be informed by “a broad spectrum of ideas.” The Report begins by explaining the genesis of today’s Court reform debate, including by identifying developments that gave rise to President Biden’s decision to issue the April 2021 Executive Order, particularly the debates surrounding the most recent nominations. This Introduction emphasizes that the Court’s composition and jurisprudence long have been subjects of public controversy and debate in the nation’s civic life: The Court serves as a crucial guardian of the rule of law and also plays a central role in major social and political conflicts. Its decisions have profound effects on the life of the nation. Though conflict surrounding the processes by which the President nominates and the Senate confirms Justices is not new, it has become more intensely partisan in recent years. The Introduction also articulates three common and interrelated ideas frequently invoked in reform debates and throughout the Chapters of the Report: the importance of protecting or enhancing the Court’s legitimacy; the role of judicial independence in our system of government; and the value of democracy and its relationship to the Supreme Court’s decisionmaking. These important ideas can mean different things to different people. The Introduction discusses the range of meanings ascribed to these terms, with the aim of clarifying how they are deployed in arguments for and against reform

    Photonic band gaps in materials with triply periodic surfaces and related tubular structures

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    We calculate the photonic band gap of triply periodic bicontinuous cubic structures and of tubular structures constructed from the skeletal graphs of triply periodic minimal surfaces. The effect of the symmetry and topology of the periodic dielectric structures on the existence and the characteristics of the gaps is discussed. We find that the C(I2-Y**) structure with Ia3d symmetry, a symmetry which is often seen in experimentally realized bicontinuous structures, has a photonic band gap with interesting characteristics. For a dielectric contrast of 11.9 the largest gap is approximately 20% for a volume fraction of the high dielectric material of 25%. The midgap frequency is a factor of 1.5 higher than the one for the (tubular) D and G structures

    A deep learning system accurately classifies primary and metastatic cancers using passenger mutation patterns.

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    In cancer, the primary tumour's organ of origin and histopathology are the strongest determinants of its clinical behaviour, but in 3% of cases a patient presents with a metastatic tumour and no obvious primary. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, we train a deep learning classifier to predict cancer type based on patterns of somatic passenger mutations detected in whole genome sequencing (WGS) of 2606 tumours representing 24 common cancer types produced by the PCAWG Consortium. Our classifier achieves an accuracy of 91% on held-out tumor samples and 88% and 83% respectively on independent primary and metastatic samples, roughly double the accuracy of trained pathologists when presented with a metastatic tumour without knowledge of the primary. Surprisingly, adding information on driver mutations reduced accuracy. Our results have clinical applicability, underscore how patterns of somatic passenger mutations encode the state of the cell of origin, and can inform future strategies to detect the source of circulating tumour DNA

    Genetic predisposition to ductal carcinoma in situ of the breast

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    Background: Ductal carcinoma in situ (DCIS) is a non-invasive form of breast cancer. It is often associated with invasive ductal carcinoma (IDC), and is considered to be a non-obligate precursor of IDC. It is not clear to what extent these two forms of cancer share low-risk susceptibility loci, or whether there are differences in the strength of association for shared loci. Methods: To identify genetic polymorphisms that predispose to DCIS, we pooled data from 38 studies comprising 5,067 cases of DCIS, 24,584 cases of IDC and 37,467 controls, all genotyped using the iCOGS chip. Results: Most (67 %) of the 76 known breast cancer predisposition loci showed an association with DCIS in the same direction as previously reported for invasive breast cancer. Case-only analysis showed no evidence for differences between associations for IDC and DCIS after considering multiple testing. Analysis by estrogen receptor (ER) status confirmed that loci associated with ER positive IDC were also associated with ER positive DCIS. Analysis of DCIS by grade suggested that two independent SNPs at 11q13.3 near CCND1 were specific to low/intermediate grade DCIS (rs75915166, rs554219). These associations with grade remained after adjusting for ER status and were also found in IDC. We found no novel DCIS-specific loci at a genome wide significance level of P < 5.0x10-8. Conclusion: In conclusion, this study provides the strongest evidence to date of a shared genetic susceptibility for IDC and DCIS. Studies with larger numbers of DCIS are needed to determine if IDC or DCIS specific loci exist

    Quantum gravity phenomenology at the dawn of the multi-messenger era—A review

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    The exploration of the universe has recently entered a new era thanks to the multi-messenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 “Quantum gravity phenomenology in the multi-messenger approach”, is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers.publishedVersio
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